Equipment controls (e.g., stereo, pulse generator, and other electronic equipment knobs) have been simulated for display through a graphical user interface (GUI) on a computer monitor or other display device. For example, graphical representations of stereo volume control knobs or rotary pulse generator (RPG) frequency setting knobs are conventionally displayed through the GUI as round knobs to minimize physical knobs. To adjust the settings (e.g., the volume or frequency), the user positions the cursor on the graphical representation of the knob using a PC mouse, touch pad, or other suitable cursor control device, and then clicks and holds down the PC mouse button to drag the cursor in a circular motion. This operation requires user dexterity and often many turns of the knob to achieve the required value. In addition, graphical representations of knobs are not standard for use with GUI applications and many computer users are therefore unaware of how to operate these knobs.
Text boxes are also commonly used to receive keyboard input for adjusting a setting (e.g., selecting a specific frequency) or to input a research request (e.g., the “Search” command on many databases). However, text boxes typically require the user to enter a specific numeric or text value and often do not permit the user to adjust the setting or research request without entering another value. As such, the user is required to know the specific value even if only an approximation is required or desired. In addition, keyboard input is error prone, and it takes time for the user to input the value (e.g., the user must remove their hand from the PC mouse to use the keyboard).
It is therefore a primary objective of the present invention to provide a variable control for display through a GUI that uses graphical representations of components that are familiar to an experienced computer user and that are readily understood by new users.
Another object of this invention is to provide a variable control that is easily operable with a PC mouse or other cursor control device. Yet another object is to provide the user with means to make both coarse and fine adjustments to the displayed value.